Cassava (Manihot esculenta Crantz), a highly heterozygous crop, is devastated by cassava mosaic disease (CMD). The discovery of the CMD2 dominant gene is helpful in the genetic analysis of CMD resistance. Molecular markers for CMD2 gene were used to introgress CMD resistance into Latin American cassava genotypes and validated in the field for 4 yr for stability of resistance conferred by CMD2. Field screening identified 64 Latin American genotypes with stable resistance to CMD. Resistance to CMD of two Nigerian cassava cultivars (TMS 97/2205 and TMS 98/0505) was analyzed with markers and in the field. Molecular data indicated that CMD resistance in the two Nigerian cultivars was mediated by the CMD2 gene. Results showed TMS 97/2205 to be highly resistant to CMD in three ecological zones in Nigeria. Further genetic analysis of this genotype as a source of high level of resistance to CMD using a segregating F1 population derived from a TMS 97/2205 × NR 8083 cross was initiated using 530 simple sequence repeat (SSR) markers to identify quantitative trait loci (QTL) for CMD resistance. A marker (NS198) associated with a QTL for CMD resistance, explaining 11% of the phenotypic variance observed, was identified. The combined effect of this QTL and CMD2 may account for the high level of resistance of TMS 97/2205. The resistance profile of the evaluated CMD2 genotypes in growth cycle was not uniform and was affected by genetic background. The discovery of a new QTL (CMD3) for CMD resistance in TMS 97/2205 offers new opportunities for pyramiding CMD genes for enhanced durability of CMD resistance in cassava.

We identified 27 stable loci associated with agronomic traits in spring wheat using genome-wide association analysis, some of which confirmed previously reported studies. GWAS peaks identified in regions where no QTL for grain yield per se has been mapped to date, provide new opportunities for gene discovery and creation of new cultivars with desirable alleles for improving yield and yield stability in wheat. We undertook large-scale genetic analysis to determine marker-trait associations (MTAs) underlying agronomic and physiological performance in spring wheat using genome-wide association studies (GWAS). Field trials were conducted at seven sites in three countries (Sudan, Egypt, and Syria) over 2-3 years in each country. Twenty-five agronomic and physiological traits were measured on 188 wheat genotypes. After correcting for population structure and relatedness, a total of 245 MTAs distributed over 66 loci were associated with agronomic traits in individual and mean performance across environments respectively; some of which confirmed previously reported loci. Of these, 27 loci were significantly associated with days to heading, thousand kernel weight, grain yield, spike length, and leaf rolling for mean performance across environments. Despite strong QTL by environment interactions, eight of the loci on chromosomes 1A, 1D, 5A, 5D, 6B, 7A, and 7B had pleiotropic effects on days to heading and yield components (TKW, SM, and SNS). The winter-type alleles at the homoeologous VRN1 loci significantly increased days to heading and grain yield in optimal environments, but decreased grain yield in heat prone environments. Top 20 high-yielding genotypes, ranked by additive main effects and multiplicative interaction (AMMI), had low kinship relationship and possessed 4-5 favorable alleles for GY MTAs except two genotypes, Shadi-4 and Qafzah-11/Bashiq-1-2. This indicated different yield stability mechanisms due to potentially favorable rare alleles that are uncharacterized. Our results will enable wheat breeders to effectively introgress several desirable alleles into locally adapted germplasm in developing wheat varieties with high yield stability and enhanced heat tolerance.

African yam bean (AYB) is an important but neglected and underutilized crop producing edible seeds and tubers. The poor awareness of the nutritional values of AYB constitutes one of the major problems limiting its utilization. This study was, therefore, carried out to determine the nutritional potentials of five accessions of African yam bean (TSs 125, TSs 116, TSs 86, TSs 69 and TSs 60) by analyzing their proximate composition and micronutrients (Iron (Fe), Zinc (Zn) and Selenium (Se)). The experiment was laid out in completely randomized design (CRD) with three replications. The results obtained showed significant (p < 0.05) variations in the proximate composition of the AYB accession. The crude protein was in the

To track changes in our climate over the past 40 years, three important weather elements namely; temperature, rainfall and relative humidity were analyzed. The results obtained revealed that there is a trend towards warmer temperatures, fluctuating rainfall distribution pattern and reduced relative humidly in the derived savanna ecological belt. The period, 2005-2010, represents the six warmest years in the past four decades in the derived savanna ecology. The bi-modal rainfall pattern is still in place but with a discernable shift of the second peak from September to October from 2001 to 2010. These glaring changes have implications on the development of Agriculture and preservation of biodiversity. Therefore, capacity building among native researchers to conduct locally relevant, policy-oriented research needed to support cogent decisions about adaptation and mitigation, and to provide reasonable options for the support structure required to facilitate and implement the research is imperative.

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The genetic diversity among 15 NIFOR breeding parents was assessed using 10 microsatellite markers. A high genetic diversity was observed with a total of 64 alleles including 23 rare alleles or alleles at frequencies less than 0.05. The NIFOR tenera parents recorded the highest number of rare alleles. The average observed heterozygosity and mean gene diversity across all parental groups were 0.6889 and 0.7029, respectively. Higher genetic diversity was detected among the NIFOR dura and tenera parents compared to that of the Deli dura parents in absolute terms. Analysis of molecular variance (AMOVA) showed that 87% of the total variation (p < 0.001) observed was due to differences among parents. Rogers' genetic distance ranged from 0.2988 to 0.8000 (mean = 0.5570). The dendrogram constructed on the basis of Rogers' genetic distance clustered the parents in three groups. They generally clustered in heterotic manner rather than by geographic origins. The groupings obtained through PCoA confirmed the results obtained by cluster analysis. The results obtained are strong assets for NIFOR breeding programme.

Drought is a major constraint to rice (Oryza spp.) production in sub‐Saharan Africa. Oryza glaberrima Steud., the cultivated rice species that originated from West Africa, is well‐adapted to its growing ecologies. This study was initiated to identify promising O. glaberrima accessions tolerant to lowland drought stress from the 2106 accessions held at the AfricaRice Genebank. Screening was done over a 3‐yr period in West Africa using standardized protocol and involved evaluating for grain yield under drought and/or irrigated conditions, selecting the high‐yielding lines, and repeating the testing with the newly selected lines. Four accessions (TOG 7400, TOG 6520, TOG 6519‐A, and TOG 7442‐B) with consistently higher grain yield under drought stress and irrigated conditions were selected. These four accessions originated from three countries in West Africa, namely, Ghana, Liberia, and Nigeria. The selected O. glaberrima accessions could be used as donors in breeding for drought tolerance in rice.

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